As related art regarding coils for use in rotating electrical machines for automobiles etc., Patent Document 1 describes a technique of a rotating electrical machine having a stator. In the technique of Patent Document 1, the coil having the crank shaped portions is formed by winding a rectangular conductor around a hexagon bobbin to form a winding and then processing the winding using forming dies. The stator is manufactured by placing the coil having the crank shaped portions in a stator core.
Patent Document 2 describes a technique in which two coils of the same phase are connected by a bridge wire, and are placed in adjoining slots of the stator core so that the loops of the two coils of the same phase partially overlap each other.